Apparatus for manufacturing a continuous stringer for a sliding clasp fastener

ABSTRACT

A strand of plastics material is converted into a slide fastener stringer by apparatus including a device for coiling the strand on a mandrel; a pair of wheels toothed according to the desired spacing of the elements in the stringer, the reduced terminating end of the mandrel engaging between the wheels; a braking member in the reception area of the pair of wheels on one side of the mandrel; a heatable shaping wheel having peripheral recesses between radial cross pieces to receive the elements, and pins projecting between the elements to support the elementinterconnecting portions of the coiled strand. A kinking disc cooperates with the shaping wheel by means of teeth which face the pins of the shaping wheel and the interconnecting portions supported on the pins and align the same in the longitudinal direction of the stringer.

United States Patent Popovitsch 51 May 1, 1973 APPARATUS FOR MANUFACTURING A [56] 7 References Cited CONTINUOUS STRINGER FOR A. UNITED STATES PATENTS SLIDING CLASP FASTENER 3,077,001 2/l963 Yoshida "29/410 x [75] Inventor: Ernst Popovitsch, Stuttgart- 3,634,922 1/1972 Burbank et al. ..29/207.5 X

Steckfeld, Germany Primary Examiner-Thomas l-l. Eager [73] Assignee: Dr. Karl F. Nagele Feinmaschinen- Atwmey HanS Berman bau, Stuttgart, Germany 22 Filed: June 8, 1971 1 ABSTRACT Appl. No.: 151,017

Related U.S. Application Data Division of Ser. No. 33,469, April 30, i970, Pat. No. 3,666,851

Foreign Application Priority Data A strand of plastics material is converted into a slide fastener stringer by apparatus including a device for coiling the strand on a mandrel; a pair of wheels toothed according to the desired spacing of the elements in the stringer, the reduced terminating end of the mandrel engaging between the wheels; a braking member in the reception area of the pair of wheels on one side of the mandrel; a heatable shaping wheel having peripheral recesses between radial cross pieces to receive the elements, and pins projecting between the elements to support the element-interconnecting portions of the coiled strand. A kinking disc cooperates with the shaping wheel by means of teeth which face the pins of the shaping wheel and the interconnecting portions supported on the pins and align the same in the longitudinal direction of the stringer.

8 Claims, 8 Drawing Figures Patented 'May 1, 1973 3,729,800

3 Sheets-Sheet 1 Patented May 1, 1973 3 Sheets-Sheet 2 i I! v mm I Ell I L 4. 4 III- M] L./ r

H 1 l Wm Patented May 1, 1973 3,729,800

3 Sheets-Sheet 5 APPARATUS FOR MANUFACTURING A CONTINUOUS STRINGER FOR A SLIDING CLASP FASTENER This application is a division of the copending application Ser. No. 33,469, filed on Apr. 30, l970, and now US. Pat. No. 3,666,853.

The present invention relates to apparatus for manufacturing a continuous stringer for a sliding clasp fastener from a shaped strand of a plastics material, which has a periodically varying angle of inclination, being coiled continuously on a fixed mandrel and subsequently withdrawn therefrom.

The construction of such a stringer, which comprises a plurality of fastener elements joined by interconnecting portions and made from a filament that is basically coiled, preferably into the shape of a helix, necessitates a particularly strong deformation, which exceeds the amount at present usual for making such stringers.

It is known to manufacture sliding clasp fastener stringers from a plastics material ;in the shape of deformed helices in such a manner that, after coiling the material into a helix having an approximately regular angle of inclination, the parts of the stringer adjacent the coupling surfaces formed thereon can be made approximately without inclination by the insertion of curved cylinders, cams, or profiled and heated wheels so that the connections between the individual coupling elements of the stringer, i.e. theinclined parts or portions, are located in the rearward area of the helix facing the coupling surfaces. Should, however, the inclined parts which connect the coupling elements together not run in the rearward region of the helix actually inclined to its longitudinal axis, but in the central area of the elements, i.e. between the front and rear reverse turn of the profiled strand, the known deformation measures are not sufficient for economic manufac ture. More particularly, it was not possible, with the hitherto known apparatus for deforming stringers, to construct these interconnecting parts so that they extend from loop to loop approximately parallel to the longitudinal axis of the row of elements in the form of cross-pieces.

It is an object of the present inventionto provide simple means for bringing about a particularly strong deformation of a helix into a closed shape, preferably of the described configuration. It is a further object to provide simple means for bringing about the withdrawal of the coiled plastics strand from the fixed mandrel and, at the same time, to preform the stringer.

The invention consists, therefore, in apparatus for manufacturing a continuous sliding clasp fastener stringer from a shaped strand of a suitable plastics material coiled into a helix on a fixed mandrel. The helix is braked at one side and withdrawn at the other side in the area of a cross-sectional reduction of the mandrel and preformed by a pair of toothed wheels into individual elements and element-interconnecting portions. The stringer is fed after the free end of the mandrel into a heated shaping wheel having peripheral recesses to receive the elements and also pins engageable therein. The element-interconnecting portions are deformed by means of at least one toothed kinking disc said connecting portions being applied against said pins of the shaping wheel by said toothed disc or discs in such a manner that the completed connecting portions run approximately parallel to the longitudinal axis of the stringer.

Furthermore, the stringer is provided with coupling surfaces in the area of the preforming toothed wheels by means of an intermittently operable stamping die.

In order that the invention may be more clearly understood, reference will now be made to the accompanying drawings which show certain aspects thereof by way of example, and in which:

FIG. I shows a side view of the complete apparatus,

FIG. 2 shows a side view of a part of the apparatus being used for withdrawing 'the helically shaped stringer for deforming and stamping, part of the apparatus being removed to make the showing clearer,

FIG. 3 shows a section through the stamping device along the line III-III of FIG. 2,

FIG. 4 shows a plan view of part of the apparatus according to FIG. 2,

FIGS. 5 and 6 show cross-sections through various parts of the coiling mandrel,

FIG. 7 shows a section along the line VII-VII of FIG. 8 made at right angles to the axis of rotation through the periphery, shown in development of the heated shaping wheel having a toothed wheel in engagement therewith, and

FIG. 8 shows a section along the line VIII-VIII of FIG. 7.

Referring now to the drawings, a shaped strand 1 of a suitable plastics material is drawn off a feed spool 2 and fed into a magnetically heated winding head 3, in a stationary part 5 of which is secured a coiling mandrel 6. The plastics filament 1 is fed through a rotating ring 4 of the winding head 3 and wound into a helix about the fixed winding mandrel 6. The convolutions thrust themselves forward and arrive between preforming wheels 7 and 8 (FIG. 4). These latter are peripherally provided with transverse gaps 9 at predetermined intervals depending upon the desired spacing of the fastener elements. A gap is provided between the preforming wheels 7 and 8 which corresponds only to the width of the coiling mandrel 6 at its end 6b which is tapered. Thus, the tapered end 6b of the mandrel is supported from opposite sides, while the coil passes through and the arrangement ensures a diametrical pressure on the convolutions thus assisting in forming coupling surfaces 14, as the helix passes between the wheels.

The effective stamping of the coupling surfaces 14, however, also necessitates a stamping die 15 (FIGS. 1 and 2). An adjustable backing block 16 which covers considerably more windings than the die 15, supports the stamping pressure and also the mandrel at 6b. By adjusting the backing block 16 by means of an eccentric disc 17, the height of the coupling surfaces 14 can be adjusted to any desired degree. Since the coupling surface 14 is stamped before the fixing operation, i.e. before the helix enters into a heated wheel or drum 18, the amount of material which is needed for the inclined portion 11 or 19 connecting the fastener elements has to be taken into account during the stamping operation. This extra material is made available during winding, due to the cross-sectional shape of the thicker part 60 of the mandrel. The mandrel is tapered at 6b to a decreased cross-section in the reception area of the preforming wheels 7 and 8. An annular groove 10 in the preforming wheel 8 offers room for the connecting portion 11 (FIG. 2) as yet lying at an oblique angle. A resilient pointed braking member 23 presses the convolutions of the helix 12 in the direction of the preforming wheel 8, so that they are engaged first by the preforming wheel 8. By this arrangement, moreover, the convolution is slightly offset so that its diametrical portion facing the preforming wheel 7 can engage therein more efficiently and without error.

The preforming so achieved, with the obliquely inclined portions ll, is not permanent since the material can still spring back.

The end 6b of the winding mandrel leads tangentially into the heated shaping wheel or drum 18. This latter consists of discs 18a, 18b and 180 (FIG. 33). The disc 18a is provided with cross-pieces 20 whose distance from one another corresponds exactly to the desired spacing of the elements in the finished fastener. The cross-pieces 20 are of the same height as the stringer. The disc 180 has pins 20: which correspond to the spacing of the cross-pieces 20 on the disc 180, but are only as high as the inclined portions 19 of the stringer allow. The base of an annular groove 22 formed between the discs 18a and 18c is formed by the peripheral surface of the central disc 18b. This groove receives the end 6b of the mandrel and also the coupling surfaces 14. It also offers space for a stripper 24.

The ultimate shape and direction of the connecting portions 19 is achieved in the heated shaping wheel 18. To this end, toothed discs 25 and 26 are arranged on the periphery of the heating wheel 18. These latter have teeth 27, which run synchronously with the pins 21. The inclined portion 19 is formed and directed between the teeth 27 and the pins 21. Slightly inclined surfaces 28 on the pins 21 effect formation of a protuberance 29 on the inclined portions 19 of the stringer. This latter offers the advantage that when loading the stringer sewn to its carrier tape, the seam cannot slip. The protuberance 29 is also used for anchoring the sewing thread.

An exact shape and direction of the inclined portion 19 connecting the elements can best be achieved by rerolling, by means of additional toothed discs similar to 25, 26, one behind the other. The shape of the teeth 27 then differs from disc to disc. The teeth 27 of the first disc 25 are slender and pointed and those of the last one 26 rather blunt.

The stringer is withdrawn from the heated wheel by means of the stripper 24. At the exit point, the stringer is initially cooled by a stream of air, ensuring the correct spacing of the elements of the stringer. Complete cooling of the stringer is effected in the open air. It is advantageous to apply a slight stress by a light roller 30 for this purpose, so that twisting is avoided as far as possible. In order to decrease or remove the twist on a finished fastener, it is advisable to coil one stringer of the fastener, for example, to the right and the other to the left.

It has proven advantageous to double up the machines side by side, for which purpose a stringer closing device 31 is provided at the end of the machines to draw both the produced stringers together to form a completed chain. This has the advantage that complete cooling off can occur in the closed position of the two cooperating stringers, and the tensions within the stringers compensate each other. The finished chain is either wound on a spooling member 32 under slight stress or the chain can be fed slack into a container from which it is removed for sewin on to the tapes. All movable parts of the machine are riven by an ad ustable motor 33 and run in synchronism.

What we claim is: I

1. Apparatus for making a slide fastener stringer having spaced elements and elementinterconnecting portions from a continuous strand of plastics material, said apparatus comprising:

a. a coiling device, including a mandrel for smoothly guiding the stringer and having a terminating end of reduced cross-section with respect to its commencing end,

. a pair of toothed wheels whose teeth are located at intervals corresponding to the spacing of the individual elements, the terminating end of said mandrel engaging between said wheels,

. a braking member in the reception area of said pair of toothed wheels and located to one side of said mandrel,

a heatable shaping wheel or drum having peripheral recesses between radial cross-pieces to receive the elements, and pins projecting between the elements which support the element-interconnecting portions, and at least one toothed kinking disc working in conjunction with said shaping wheel and having teeth which face said pins of the shaping wheel and form said portions supported on said pins and align the same in the longitudinal direction of the stringer.

2. Apparatus as claimed in claim 1, wherein a stamping die is arranged in the common area of engagement of said pair of toothed wheels, for stamping coupling surfaces on the convolutions of the coiled strand.

3. Apparatus as claimed in claim 2, wherein a backing block is arranged on the side of the coiled strand opposite said stamping die.

4. Apparatus as claimed in claim 1, wherein said mandrel is provided in the coiling area with a groove increasing the coiling periphery, which is taken approximately to the engaging region of the said pair of toothed wheels.

5. Apparatus as claimed in claim 1, wherein said shaping wheel comprises three discs, of which the central one forms the base of an annular groove receiving the stringer, while one of the side discs has said radial cross-pieces, said cross-pieces receiving the elements therebetween, and the other side disc carrying said pins to support said interconnecting portions.

6. Apparatus as claimed in claim 5, wherein each pin has a chamfered end by which a protuberance is formed on one end of each interconnecting portion.

7. Apparatus as claimed in claim 1, wherein the kinking disc has teeth with forwardly directed oblique flanks and straight lagging flanks effective in the coiling direction.

8. Apparatus as claimed in claim 1. which is duplicated, the pair being arranged side by side for simultaneous manufacture of two stringers that can be united for common cooling. 

1. Apparatus for making a slide fastener stringer having spaced elements and element-interconnecting portions from a continuous strand of plastics material, said apparatus comprising: a. a coiling device, including a mandrel for smoothly guiding the stringer and having a terminating end of reduced crosssection with respect to its commencing end, b. a pair of toothed wheels whose teeth are located at intervals corresponding to the spacing of the individual elements, the terminating end of said mandrel engaging between said wheels, c. a braking member in the reception area of said pair of toothed wheels and located to one side of said mandrel, d. a heatable shaping wheel or drum having peripheral recesses between radial cross-pieces to receive the elements, and pins projecting between the elements which support the elementinterconnecting portions, and e. at least one toothed kinking disc working in conjunction with said shaping wheel and having teeth which face said pins of the shaping wheel and form said portions supported on said pins and align the same in the longitudinal direction of the stringer.
 2. Apparatus as claimed in claim 1, wherein a stamping die is arranged in the common area of engagement of said pair of toothed wheels, for stamping coupling surfaces on the convolutions of the coiled strand.
 3. Apparatus as claimed in claim 2, wherein a backing block is arranged on the side of the coiled strand opposite said stamping die.
 4. Apparatus as claimed in claim 1, wherein said mandrel is provided in the coiling area with a groove increasing the coiling periphery, which is taken approximately to the engaging region of the said pair of toothed wheels.
 5. Apparatus as claimed in claim 1, wherein said shaping wheel comprises three discs, of which the central one forms the base of an annular groove receiving the stringer, while one of the side discs has said radial cross-pieces, said cross-pieces receiving the elements therebetween, and the other side disc carrying said pins to support said interconnecting portions.
 6. Apparatus as claimed in claim 5, wherein each pin has a chamfered end by which a protuberance is formed on one end of each interconnecting portion.
 7. Apparatus as claimed in claim 1, wherein the kinking disc has teeth with forwardly directed oblique flanks and straight lagging flanks effective in the coiling direction.
 8. Apparatus as claimed in claim 1, which is duplicated, the pair being arranged side by side for simultaneous manufacture of two stringers that can be united for common cooling. 